# -*- coding: utf-8 -*-

# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
from scrapy.http import HtmlResponse
class NanjinFilesSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, dict or Item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request, dict
        # or Item objects.
        pass

    def process_start_requests(self, start_requests, spider):
        # Called with the start requests of the spider, and works
        # similarly to the process_spider_output() method, except
        # that it doesn’t have a response associated.

        # Must return only requests (not items).
        for r in start_requests:
            yield r

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)


class NanjinFilesDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.
    # @classmethod
    # def from_crawler(cls, crawler):
    #     # This method is used by Scrapy to create your spiders.
    #     s = cls()
    #     crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
    #     return s

    def process_request(self, request, spider):
        if spider.name == 'getfile':
            spider.bro.get(request.url)   #使用浏览器访问爬取网址
            iframe = spider.bro.find_element_by_xpath("//div[@class='gl_main_right']/iframe")  #定位到iframe
            spider.bro.switch_to.frame(iframe)  #最重要的，切换到iframe的html中
            body = spider.bro.page_source  #获取iframe中的html内容
            #重新将html的xml封装为response对象传给spider
            return HtmlResponse(url=spider.bro.current_url, body=body, encoding='utf-8', request=request)
        else:
            return None

    # def process_response(self, request, response, spider):
    #     if spider.name == 'getfile':
    #         spider.bro.get(request.url)   #使用浏览器访问爬取网址
    #         iframe = spider.bro.find_element_by_xpath("//div[@class='gl_main_right']/iframe")  #定位到iframe
    #         spider.bro.switch_to.frame(iframe)  #最重要的，切换到iframe的html中
    #         body = spider.bro.page_source  #获取iframe中的html内容
    #         #重新将html的xml封装为response对象传给spider
    #         return HtmlResponse(url=spider.bro.current_url, body=body, encoding='utf-8', request=request)
    #     else:
    #         return response
    #
    # def process_exception(self, request, exception, spider):
    #     # Called when a download handler or a process_request()
    #     # (from other downloader middleware) raises an exception.
    #
    #     # Must either:
    #     # - return None: continue processing this exception
    #     # - return a Response object: stops process_exception() chain
    #     # - return a Request object: stops process_exception() chain
    #     pass
    #
    # def spider_opened(self, spider):
    #     spider.logger.info('Spider opened: %s' % spider.name)